mod_slack_webhooks/mod_slack_webhooks.lua

   1 -- Allow Slack-style incoming and outgoing hooks to MUC rooms
   2 -- Based on mod_muc_intercom and mod_post_msg
   3 -- Copyright 2016-2017 Nathan Whitehorn <nwhitehorn@physics.ucla.edu>
   4 --
   5 -- This file is MIT/X11 licensed.
   6
   7 module:depends"http"
   8
   9 local msg = require "util.stanza".message;
  10 local jid = require "util.jid";
  11 local now = require "util.datetime".datetime;
  12 local json = require "util.json"
  13 local formdecode = require "net.http".formdecode;
  14 local http = require "net.http";
  15 local dataform = require "util.dataforms";
  16
  17 local mod_muc = module:depends"muc";
  18 local rooms = rawget(mod_muc, "rooms");
  19 local get_room_from_jid = rawget(mod_muc, "get_room_from_jid") or
  20         function (room_jid)
  21                 return rooms[room_jid];
  22         end
  23
  24 local button_ns = "xmpp:prosody.im/community/mod_slack_webhooks#buttons";
  25 local routing = module:get_option("outgoing_webhook_routing") or {};
  26 local listen_path = module:get_option("incoming_webhook_path") or "/webhook";
  27 local default_from_nick = module:get_option("incoming_webhook_default_nick") or "Bot";
  28
  29 function postcallback(_, code)
  30         module:log("debug", "HTTP result %d", code)
  31 end
  32
  33 function check_message(data)
  34         local stanza = data.stanza;
  35
  36         local this_room = get_room_from_jid(stanza.attr.to);
  37         if not this_room then return; end -- no such room
  38
  39         local from_room_jid = this_room._jid_nick[stanza.attr.from];
  40         if not from_room_jid then return; end -- no such nick
  41
  42         local from_room, from_host, from_nick = jid.split(from_room_jid);
  43
  44         local body = stanza:get_child("body");
  45         if not body then return; end -- No body, like topic changes
  46         body = body and body:get_text(); -- I feel like I want to do `or ""` there :/
  47
  48         if not routing[from_room] then
  49                 return;
  50         end
  51
  52         local json_out = {
  53                 channel_name = from_room,
  54                 timestamp = now(),
  55                 text = body,
  56                 team_domain = from_host,
  57                 user_name = from_nick,
  58         };
  59
  60         local form = stanza:get_child("x", "jabber:x:form");
  61         if form and form.attr.type == "submit" then
  62                 local callback_id, button_name, button_value;
  63                 for field in form:childtags("field") do
  64                         if field.attr.var == "callback_id" then
  65                                 button_name = field:get_child_text("text");
  66                         elseif field.attr.var == "button_name" then
  67                                 button_name = field:get_child_text("text");
  68                         elseif field.attr.var ~= "FORM_TYPE" or field:get_child_text("text") ~= button_ns then
  69                                 callback_id, button_name, button_value = nil, nil, nil;
  70                                 break;
  71                         end
  72                 end
  73                 if callback_id and button_name and button_value then
  74                         json_out.callback_id = callback_id;
  75                         json_out.actions = {
  76                                 { type = "button", name = button_name, value = button_value }
  77                         };
  78                 end
  79         end
  80
  81         local stanzaid = stanza:get_child("id");
  82         if stanzaid and string.sub(stanzaid,1,string.len("webhookbot"))=="webhookbot" then
  83                 json_out["bot_id"] = "webhookbot";
  84         end
  85
  86         json_out = json.encode(json_out)
  87         local url = routing[from_room];
  88         module:log("debug", "message from %s in %s to %s", from_nick, from_room, url);
  89         if url == "DEBUG" then
  90                 module:log("debug", "json_out = %s", json_out);
  91                 return;
  92         end
  93         local headers = {
  94                 ["Content-Type"] = "application/json",
  95         };
  96         http.request(url, { method = "POST", body = json_out, headers = headers }, postcallback)
  97 end
  98
  99 module:hook("message/bare", check_message, 10);
 100
 101 local function route_post(f)
 102         return function(event, path)
 103                 local bare_room = jid.join(path, module.host);
 104                 if not get_room_from_jid(bare_room) then
 105                         module:log("warn", "mod_slack_webhook: invalid JID: %s", bare_room);
 106                         return 404;
 107                 end
 108                 -- Check secret?
 109                 return f(event, path)
 110         end
 111 end
 112
 113 local function handle_post(event, path)
 114         local request = event.request;
 115         local headers = request.headers;
 116
 117         local body_type = headers.content_type;
 118         local post_body;
 119         if body_type == "application/x-www-form-urlencoded" then
 120                 post_body = formdecode(request.body);
 121         elseif body_type == "application/json" then
 122                 post_body = json.decode(request.body)
 123                 if not post_body then
 124                         return 420;
 125                 end
 126         else
 127                 return 422;
 128         end
 129         local bare_room = jid.join(path, module.host);
 130         local dest_room = get_room_from_jid(bare_room);
 131         local from_nick = default_from_nick;
 132         if post_body["username"] then
 133                 from_nick = post_body["username"];
 134         end
 135         local sender = jid.join(path, module.host, from_nick);
 136         module:log("debug", "message to %s from %s", bare_room, sender);
 137         module:log("debug", "body: %s", post_body["text"]);
 138         local message = msg({ to = bare_room, from = sender, type = "groupchat", id="webhookbot" .. now()},post_body["text"]);
 139
 140         if type(post_body["attachments"]) == "table" then -- Buttons?
 141                 -- luacheck: ignore 631
 142                 -- defensive against JSON having whatever data in it, enjoy
 143
 144                 for _, attachment in ipairs(post_body["attachments"]) do
 145                         if type(attachment) == "table" and type(attachment.actions) == "table" and type(attachment.callback_id) == "string" then
 146                                 local buttons = {};
 147                                 local button_name;
 148                                 for _, action in ipairs(attachment.actions) do
 149                                         if type(attachment.text) == "string" then
 150                                                 buttons.label = attachment.text;
 151                                         end
 152                                         if type(action) == "table" and action.type == "button" and type(action.name) == "string" and type(action.value) == "string" then
 153                                                 if not button_name then
 154                                                         button_name = action.name;
 155                                                 end
 156                                                 if button_name == action.name then
 157                                                         local button = {
 158                                                                 value = action.value;
 159                                                         };
 160                                                         if type(action.text) == "string" then
 161                                                                 button.label = action.text;
 162                                                         end
 163                                                         table.insert(buttons, button);
 164                                                 end
 165                                         end
 166                                 end
 167                                 if button_name then
 168                                         message:add_direct_child(dataform.new({
 169                                                 {
 170                                                         type = "hidden", name = "FORM_TYPE",
 171                                                         value = button_ns,
 172                                                 },
 173                                                 {
 174                                                         type = "hidden", name = "callback_id",
 175                                                         value = attachment.callback_id,
 176                                                 },
 177                                                 {
 178                                                         type = "hidden", name = "button_name",
 179                                                         value = button_name,
 180                                                 },
 181                                                 {
 182                                                         type = "list-single", name = "buttons",
 183                                                         value = "", -- FIXME util.dataforms can't do options without a value
 184                                                         options = buttons;
 185                                                 }
 186                                         }):form());
 187                                         break;
 188                                 end
 189                         end
 190                 end
 191         end
 192         dest_room:broadcast_message(message, true);
 193         return 201;
 194 end
 195
 196 module:provides("http", {
 197         default_path = listen_path;
 198         route = {
 199                 ["POST /*"] = route_post(handle_post);
 200                 OPTIONS = function(e)
 201                         local headers = e.response.headers;
 202                         headers.allow = "POST";
 203                         headers.accept = "application/x-www-form-urlencoded, application/json";
 204                         return 200;
 205                 end;
 206         }
 207 });
 208